Better batten down your hatches, silverbak; you may soon be the target of a lot of random, ignorant flames.
If I recall correctly, enabling client SMP has almost no effect in performance besides in Mac OSX systems. Could be wrong, though.
I'd personally be willing to do it for you, but I'm on an I386 system. I did manage to compile an SMP client with ease (r1112), but r_smp does not work on my system, which does have a dual-core processor. Go figure.